The present invention relates to a member (hereinafter referred to as armature stator) which comprises a coil and an iron core, such as an electromagnet, an induction coil-type displacement sensor, etc.
Among the armature stators of this kind, those which are placed in an environment of high temperature and very high vacuum conditions have heretofore used a coil whose surface is coated with an inorganic material. When directly mounted on the iron core, however, the surface of the coil is scratched and the insulating property of the coil is destroyed. As shown in FIG. 3, therefore, the coil has been mounted on an iron core 3 via a bobbin 2. Here, the bobbin 2 is made of a material having an insulating property and is firmly press-fitted onto the iron core 3.
However, according to such a conventional armature stator in which the coil 1 is mounted on the iron core 3 via the bobbin 2, the armature stator tends to become bulkier by the thickness of the bobbin 2, which results in an increase in the leakage of magnetic flux. Moreover, since the bobbin 2 is fixed onto the iron core 3 by press fitting, the press-fit joined portion inevitably becomes loosened, and reliability of the armature stator is lost.